1. Field of the Invention
The present invention relates to a metal heat exchanger such as the so-called multi-flow type aluminum heat exchanger suitably used for a car air-conditioning condenser and the like.
2. Prior Art
As the so-called multi-flow type heat exchanger such as a car air-conditioning condenser, a heat exchanger shown in FIGS. 9 and 10 is generally known. The heat exchanger includes a pair of hollow headers 101 and 101 arranged in parallel, a plurality of flat tubes 102 disposed between the headers 101 and 101 and connected thereto and corrugated fins 103 each disposed between the adjacent tubes 102. As shown in FIG. 10, each tube 102 is connected to the headers 101 such that both end portions of the tube 102 are brazed to the headers 101 in a state that the end potions are inserted into the circumferentially extending slit-shaped tube fitting aperture 104 formed in the opposed surfaces of the headers 101.
Furthermore a corrugated fin 103 is disposed at the outside surface of the outermost tube 102 in order to improve the heat exchange efficiency, and a side plate 105 is disposed at the outside surface of the corrugated fin 103 for the purpose of protecting the fin 103 and the like. As shown in FIG. 10, at both ends of this side plate 105, an outwardly protruded fitting portion 106 having a small width is formed respectively. This side plate 105 is integrally brazed to the headers 101 in a state that the fitting portion 106 is fitted in the side plate fitting aperture 107 having a narrow width formed in the opposed surfaces of the headers 101 and 101. The reference numeral 110 denotes a partitioning plate, 111 denotes an inlet pipe and 112 denotes an outlet pipe.
According to the heat exchanger having the aforementioned conventional structure, it is required to provide the protruded fitting portions 106 at both ends of the side plate 105. However, it is technically difficult to form such a protruded fitting portion 106 by end processing, resulting in deteriorated productivity and an increased cost.
Furthermore, it is required to form two different types of apertures in the external surface of each header 101, i.e., side plate fitting apertures 107 for receiving the protruded fitting portion 106 and the tube fitting apertures 104 for receiving the tube 102. In other words, it is required to use different tools for forming the side plate fitting apertures 107 and the tube fitting apertures 104, which results in deteriorated productivity and an increased cost.
The present invention is made in view of the aforementioned technical background and aims to provide a heat exchanger which is excellent in productivity and capable of decreasing the manufacturing cost by eliminating the necessity of forming a special fitting configuration at end portions of a side plate and enhancing the workability for forming side plate fitting apertures and tube fitting apertures.
Another purpose of the present invention will be apparent from the following embodiment.
According to the first aspect of the present invention, a heat exchanger includes a hollow header having a plurality of tube fitting apertures arranged in line, a plurality of tubes communicated with the header, each tube having one end fitted in a corresponding tube fitting aperture, a fin disposed at an outside of an outermost tube, and a side plate disposed at an outside of the fin, wherein the header is further provided with a side plate fitting aperture having the same or approximately the same configuration as that of the tube fitting aperture, wherein a header insertion end portion of the side plate is formed into a cross-sectional peripheral configuration corresponding to a cross-sectional peripheral configuration of the side plate fitting aperture, and wherein the header insertion end portion of the side plate is fitted in the side plate fitting aperture and secured thereto.
According to the second aspect of the present invention, a heat exchanger includes a pair of hollow headers arranged in parallel, a plurality of tubes disposed between the headers and communicated with the headers with opposite end portions fitted in tube fitting apertures formed in opposed surfaces of the pair of headers, fins disposed between adjacent tubes and at an outside of an outermost tube, and a side plate disposed at an outside of an outermost fin with opposite end portions fitted in side plate fitting apertures formed in opposed surfaces of the pair of headers, wherein a header insertion end portion constituting one of both end portions of the side plate is formed into the same or approximately the same cross-sectional peripheral configuration as that of an end portion of the tube, and wherein the side plate fitting aperture is formed into the same or approximately the same configuration as that of the tube fitting aperture.
In the heat exchanger according to the present invention, since the side plate fitting aperture and the tube fitting aperture formed in the headers have the same or approximately the same configuration, the aperture forming operations can be completed by forming a plurality of the same or approximately the same apertures in the header, and therefore it is not required to form a conventional side plate fitting apertures different from the tube fitting apertures. This enhances the workability of forming fitting apertures in the header, which in turn reduces the manufacturing cost. Furthermore, since the end portion of the side plate is formed into the same or approximately the same cross-sectional peripheral configuration as that of an end portion of the tube, it is not required to perform specific end portion processing to an end portion of the side plate for forming a protruded fitting portion which is technically difficult. Accordingly, the quality of product can be improved and the cost can be decreased because of the enhanced workability.
As the fin, it is preferable to use a corrugated fin constituted by an aluminum brazing sheet comprising a core member and brazing materials coated on one side or both sides of the core member.
It is preferable that the side plate is provided with a header inserting portion having a contacting piece vertically extending relative to the side plate, and wherein the side plate is secured to the header with a header fitting surface of the contacting piece fitted to an external surface of the header. In this case, since the joining area increases when the header fitting surface of the contacting piece is secured to the external surface of the header, the joining strength increases notably. Furthermore, the existence of the contacting piece effectively prevents the contraction in the right-and-left direction (the longitudinal direction of the side plate) at the time of joining such as brazing.
It is preferable that the contacting piece is extended toward an inside of the side plate. In this case, it becomes unnecessary to newly provide a contacting piece fitting space at the tip end position of the external surface of the header (at the position located outside the side plate), resulting in a shortened header length, which in turn can meet the demand of compactness of a heat exchanger.
It is preferable that the contacting piece is formed by bending a cut-part of a widthwise edge portion of the header inserting end portion. In this case, there is a merit that the productivity can be improved regardless of the existence of the contacting piece.
It is preferable that the header inserting end portion of the side plate is formed into a tapered shape having a width decreasing toward a tip thereof. By forming the header inserting end portion into such a tapered shape, the insertion of the end portion of the side plate into the side plate fitting aperture can be performed smoothly, and the side plate can be fitted into the headers in a positioned state.
Alternatively, the header inserting end portion of the side plate may have a first tapered portion as an insertion guide at a tip end thereof and a second tapered portion for an insertion amount restricting portion at an inside position of the header inserting end portion. In this case, there are merits that it becomes easy to insert the side plate into the header and the assembly work can be done easily because of the regulated header insertion amount.
The side plate may have a width which is the same or approximately the same as a width of the tube and a thickness which is the same or approximately the same as a height of the tube.
The aforementioned heat exchanger can be preferably used for a condenser in a refrigeration cycle in which a refrigerant compressed by a compressor is condensed by a condenser, the condensed refrigerant is decompressed by passing through a decompressing device, and the decompressed refrigerant is evaporated by an evaporator and then returned to the compressor.